fatuous

American  

[fach-oo-uhs] / ˈfætʃ u əs /

adjective

1. foolish or inane, especially in an unconscious, complacent manner; silly; witless.

   Synonyms:

   dull-witted, dull, dense, dim, brainless

2. Archaic. unreal; illusory.

---

fatuous British  

/ ˈfætjʊəs /

adjective

1. complacently or inanely foolish

---

Usage

What are other ways to say fatuous? The adjective fatuous describes people or things that are foolish or inane, especially in an unconscious, complacent manner. Do you know when to use fatuous, foolish, silly, inane, stupid, and asinine? Find out on Thesaurus.com.

Other Word Forms

• fatuously adverb
• fatuousness noun

Etymology

Origin of fatuous

First recorded in 1625–35; from Latin fatuus “silly, foolish, idiotic”; -ous

Explanation

Fatuous means lacking intelligence. When your mother outlaws calling your brother stupid, use fatuous instead. Fatuous derives from the Latin fatuus meaning "foolish." It sounds like it should have something to do with being fat, but it actually has no relation to size. Fatuus itself comes from a root that also gave us "debate" and this might be a good way to remember it. You want to debate someone who's fatuous, because they are unintelligent, silly and even a bit conceited, so they probably won't be very persuasive debaters. Just don't call them fatuous to their face. Even if they don't know what it means, it's just not nice!

Example Sentences

But at least they made an attempt, however fatuous, to persuade the American people and the country’s international allies that there was a reason for doing so.

From Salon • Feb. 24, 2026

You’d be unwise to look to the movies for economic insight—this one amounts to an extended fatuous argument that an individual who behaved like a corporate restructuring would be a psychopath.

From The Wall Street Journal • Dec. 24, 2025

On Monday, he repeated the fatuous nonsense he's spewed for ages:

From Salon • Apr. 9, 2025

The money he makes, running the farm with his unmarried niece, goes to support life in the city for his fatuous, gouty sort-of-ex-brother-in-law, an art professor who “knows nothing about art.”

From New York Times • Apr. 24, 2024

Supermarket tabloids never provide an end-of-year list of false predictions by psychics, nor do the more upscale New Age periodicals, which, despite a veneer of sophistication, are just as fatuous.

From "Innumeracy: Mathematical Illiteracy and Its Consequences" by John Allen Paulos